Work holding attachment for surface grinders



Sept. 30, 1947.

C W. STRON G WORK HOLDING ATTACHMENT FOR SURFACE GRINDERS 5 A. 9 1 .0 5 n J d e l i Patented Sept. 30, 1947 WORK HOLDING ATTACHMENT FOR SURFACE GRINDERS Charles W. Strong, Wynnewood, Pa.

Application January 30, 1945, Serial No. 575,254

15 Claims. 1

This invention relates to grinding machines and a primary object of the invention is to provide an improved attachment for surface grinders by means of which this type of machine may be adapted for cylindrical grinding and allied operations.

More specifically, the invention contemplates provision of a device, in the form of an attachment for machines of the surface grinding type, for supporting the work for rotation about an axis predeterminedly disposed with respect to the normal plane of relative traverse between the grinding tool and the work.

Another object of the invention is to provide a device of the stated character wherein means is provided for adjusting the said axis of rotation of the work angularly with respect to said plane of relative traverse.

Another object of the invention is to provide a device of the aforesaid character having means for maintaining the work fixed-in said support for presentation to the grinding tool in desired positions of adjustment about said axis.

The invention further resides in certain structural and mechanical details, hereinafter set forth, by means of which the aforesaid major objects of the invention are attained and which contribute to the provision of an attachment characterized by extreme flexibility of adjustment and constituting a highly valuable precision adjunct for surface grinders capable of materially enlarging the scope of utility of machine tools of that basic type.

In the attached drawings,

Figure 1 is a side elevational view of a device made in accordance with my invention illustrated in its relation to the immediately associated elements of the grinding machine with which it is adapted to function;

Figures 2 and 3 are fragmentary side elevational views illustrating the means for adjusting the work angularly with respect to the normal plane of relative traverse between the grinding tool and the work;

Figure 4 is an enlarged sectional elevational view of the device;

. Figure 5 is an end elevational View of the dev1ce;

Figure 6 is a section on the line 6-6, Figure 4;

Figure 7 is a. fragmentary sectional view on the line l'l, Figure 4;

Figure 8 is a fragmentary sectional view illustrating a detail of the indexing device shown more particularly in Figure 5;

. Figure 91s a fragmentary exploded view in perspective of one end of the base plate of the device including the immediately associated elements;

Figure 10 is a view in perspective of the tail stock locking pin, and

Figure 11 is a fragmentary vertical sectional view illustrating a modification of the work-holding means.

With reference to the drawings, the preferred embodiment of the invention therein illustrated consists of a bed plate I, of generally rectangular form in the present instance, having an upstanding boss .or ear 2 at each corner thereof, the two sets of ears at each end of the bed plate having coaxial apertures designated in each instance by the reference numeral 3. Adjustably mounted on the bed plate I is a base plate 4, said base plate normally seating upon set screws 55 which are threaded in the bed plate I and are adjustable in the latter to vary their eifective height. The base plate 4 is adapted for pivotal connection with the bed plate I through the medium of pins 6t which are removably fitted to the apertures 3 and which project into recesses l in the ends of the base plate aligned with said apertures. Two sets of the recesses I are provided in the base plate, at the opposite ends thereof respectively, so that the pivotal connection may be established selectively at either end by simple transfer of the pins 6. Thereby, provision is made for tilting the base plate on the bed plate from either end as illustrated in Figures 2 and 3. The adjusting screws 5 are in position approximately midway between the two pivotal axes, which may be established selectively as described above, and operate with the pivot pins 6 to support the base plate in a normal plane parallel to the plane of the nether surface of the bed plate. Adjustment of the screws will correspondingly slightly modify the angular position of the base plate with respect to the operative pivot as may be required to establish the said plate accurately in a desired plane.

The bed plate I has in each side edge thereof a-longitudinal T-slot 8 in which is slidably fitted a square headed bolt 9, the threaded end of said bolt projecting outwardly beyond the edge surface of the bed plate for reception of an element II which fits slidably on the bolt and which has on its outer face a projecting cylindrical boss l2 which forms a pivot for one end of a strut element I3. Each of the strut elements has at its lower end an aperture M into which the boss l2 fits accurately, and a nut I5 is provided on the outer extremity of the bolt 9 whereby the bolt,

- 3 the slide element l i, and the strut l3 may be immobilized in any desired position of adjustment longitudinally of the slot 8. As shown in Figure 9 each of the slots 8 is provided with an openin I6 in the bottom of the bed plate I through which the square head of the bolt 9 may be introduced into the slot.

The other end of the respective struts 13, one at each side of "the :bed plate "as illustrated, :is

. pivotally. secured by means of screwllto the side of the base plate 4 at a point approximately midway between the pairs of apertures I so that the strut l3 may operate to support .the base plate in desired angular position of'adjustment about either of the alternative pivotal axes. "By loosening the nuts l5 and the screws l1,-.the;strut is free for adjustment to a position afiording the desired angularity of the baseplate, 'and it will be noted that that end of the strut :which is attached to the bed plate may be moved to either end of the-slot 8 .so as .to occupy the most favorable position withrespect .to the base ,plate for any position of the latter. Subsequent tightening of .the nut liandpreferably also of the screws I! will lock the strut to both the bedplate and the base plate and will retain the .basejplateiin theposition of angular adjustment.

Preferably, and as illustrated in Figure 7, each of the screws l1 carries a sleeve l8lhaving2an eccentriomidportion l9 which is, positioned'withinthe aperture'2l 'inithe end of'thelassociated strut i3. Beyond this eccentricbearing portion l9,thes'leeve has an enlarged knurled head 22 with radial recesses 23for reception of a suitable turningtool. Whent'he'screw I! islloosened the sleeve [8 may .be rotated about its axis Lin'the screw with the result thatithe 'eccentr'icportion 19 will :efiect .a limited angular adjustment of the base plate 4 with respect to 'thebed plate I, thus affording a fine or micrometer adjustment for the :base plate. "Subsequently, aretightening of the screwll will lockthe sleeve l8 in adjusted position.

The base plate 4 has a rectangular frame-dike extension 25 "at one en'dwithin which is'pivotally supported an .electric motor 25. mountingfor the motor comprisesa pair of lugs 26,;216 'Iwliich extend upwardly from one side of the frame 2 4 'andwhichare providedwith aligned apertures forreception 'of the trunnions '21, 21 of'a 'bl'ock 28, said block beingthus j'ournaledin the frame for pivotal "movement about an axis extending longitudinally tof'the *base'piate '4 and parallel 'to'the rotary axis '01" the motor '25. A rigid strap Zilissecured .to the'block 28 andis attached also 'tothe side of 'theimotor 25, as

illustrated in Figure 6; thus supporting the motor for pivotalmovement *about the axis' ofithe trunnions"2"l.

The motorshaft 3i projects t'hrough'aslot 32 in a standard 33, 'which standard extends upwardl-y -fi'omtherearen'd ofthe base plate 4, "and the said sha'ftl3i has attached "t'o'its extremity-a belt pulley 33 which is connected through a'belt 34 to-a pulley 35 journaled on a'sleeve tfi carried by a journal pin :31 secured in and *projecting transversely .from the -=-sai'd 'standard. A

set screw 38 lis :engageable with "the pin '36 --to lock-the pin "rigidly 1 inithe standard. The pulley 35 has as an integral part thereof adisc -3 9, this disc being zprovided'in .itszperiphery 'lWith 'a circumferential series f i'unifzorm'ly spaced "recesses 4|. fifhei-function'aofthese recesses will-be described hereinafter. The pin .31 has a conical extremity #2 whereby the ;pinrmay lfun-ction-zas t a center .pin for rota'bly supporting 1,0I18BHL1IOf La The pivotal 4 work piece 43 as hereinafter set forth. The disc 39 carries a projecting pin 44 positioned for engagement with an arm 45 on a collar 46 which is adapted to be attached through the medium of a set screw 47 to one end of the work piece 43 whereby rotation of the disc 39 will efiect also a rotation of the work piece about the axis of the pin 31.

The disc 39 also carries a pair .of projecting lugs 48 and "49 each of which has a set screw 5|. When the arm 45 of the collar 46 is positioned between the lugs 48 and 49 and the set screws 5| then turned inwardly against the oppo- ;site;sides-of the arm, the work will be immobilized with respect to the disc 39.

-ablymountedin-a boss 53 on the frame of the machine. A spring pressed detent 54 holds this latch releasably in each of two alternative positions in one of which the inner end of the latch 52 projects into one or'otherof the recesses Al in thedisc 39, thereby immobilizing'the .disc,and in'the other of which the latchis withdrawn from the;periphery of the 'disc 39 to leave the .latter free for rotation.

The base plate 4 also carries a standard 55 which carries a taper-ended center pin 56, said pin being engageable with the end of the work as illustrated in Figure '4 to thereby, in 'conjunction with the pin 42, support the'work'fl for rotation about a predetermined axisin the structure. Normally this axis will parallel the plane of the bed plate, as inFig. 4. The standard 55 comprises a pin 57 which extends upwardly through a longitudinal slot 58in the base plate 4 so that" this pin may be adjusted longitudinally of the base plate. The standardiifurther comprises a post element 59 which ismecessedfrom the'bottomfor reception of the pin 51 'asshown in Fig. 4. 'Thepost 59 and the pin "51 :are apertured for reception of a retaining pin -6|,this pin extending through said apertures andlhaving an eccentric portion 62 whichfits neatly within the aperture 63 in the pin 51. By'rotating the pin-6| the eccentric 62 may be made to relatively move the pin 51 and the post 5950 that .the liead fi i of the pin is drawn up against theunder side of the baseplate 4 and the bottom of the post 59 is drawn downwardly against the top of the baseplateso as to clamp the latter thereby to rigidly secure the standard 55 in adjusted position in the said plate. A set screw '65 enters .a circumferential recess-66 in the inner end'.of'the pin BI to retain the pin and to rigidly securelthe pin in thestandard clamping position.

The operation of the device is as follows:

-Where the surface grinder is equipped witha magnetic work table and the bed plate [is made of ferrous metal, the attachment may bemagnetically secured to the work table. Where the I said work table is the traversiblemember o'f'the grinder, the device may be positioned on the table so 'as .to bring the work piece into engagement with the grinding tool along a given-line andin the plane of traverse. Thereafter-with themotor 25 in operation to rotate the work,"the latter may be traversed in well known manner'wi-th respect to the tool to efiect a rotary grinding of the work in accordance with known principles. When the baseplatefl is resting upon the pins 5, the "rotary axis of the work will parallel the under surface of the bed plate, and also the surface of the Work .tablebf the grinder. -If grinding o'fthe work piece is desired at an'angle to this normal axis :as'in the case of the ltapered-endsof the work piece 43 shown in the drawings, the base plate may be tilted to the required angle about one or other of the pivotal axes afforded by the apertured ears 2 and the recesses l as previously set forth. By reason of the ability to pivotally adjust the base plate on the bed plate about axes at each end of the base plate, the desired angular grinding of the ends of the work piece may be effected without disturbing the work in its support.

If it be desired to grind hexagonal or other angular faces on the work piece, the work may be immobilized with the disc 39 by means of the set screws 5| as previously described and the latch 52 then utilized to anchor the disc and to index it in the various positions which the work must assume in the grinding operation.

It will be apparent that the device as described above is subject. to modification without departure from the invention. One such modification, having to do with the manner of supporting the work, is illustrated in Fig. 11. In this case the driven pulley 35a carries a collet 61 by means of which the work may be supported coaxially with the pulley and entirely from one side and independently of the tail stock. The disc 39a, which corresponds to and replaces the disc 39 of the previously described embodiment, is formed separately from the pulley and is secured thereto by means of screws 68. The pin 31 is in this case replaced by a hollow member 69 having at its outer end a flange which is confined in an annular recess between the pulley and the disc and acts to retain the pulley-disc assembly against axial displacement. The disc 39a is formed to receive the elements of the collet, as illustrated. This assembly may constitute an attachment interchangeable with the pulley and disc assembly shown injig. 4. Obviously other work-holding means, such for example as the conventional chuck, may be utilized in similar manner without departing from the inventive principle.

I claim:

1. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively traversible in a predetermined plane, said attachment comprising a base adapted to be secured to the work table, a structure mounted on said base for adjustment selectively about either of two pivotal axes fixed with respect to the base, said axes being parallel to each other and occupying a common plane parallel to the said plane of traverse, means for maintaining the said structure rigidly in the adjusted positions about each of said axes, means for supporting a work piece in said structure for rotation about an axis in a plane transversely intersecting both of said pivotal axes, and means for rotating said work.

2. An attachment for surface grinders of the type including a rotary grinding tool and a work table traversible relatively in a predetermined plane, said attach'ment comprising a base adapted to be secured to the work table, a structure mounted on said base for pivotal adjustment selectively about either of two pivotal axes parallel to said plane, means for supporting a work piece in said structure for rotation about a predetermined axis in the latter, and an adjustable strut element operative to maintain said structure in desired position of pivotal adjustment about either of said first mentioned axes.

3. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively movable in a predetermined plane,

said attachment comprising a bed plate adapted to be secured to the work table, a base member hinged to said plate for angular adjustment with respect thereto, a work support on said member, means for releasably retaining the base member in adjusted position, and micrometer adjustment means associated with the retaining member for effecting minor angular adjustments of said member with respectto the bed plate.

4. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively movable in a predetermined plane, said attachment comprising a bed plate adapted to be secured to the work table, a base member hinged to said plate for angular adjustment with respect thereto, work-supporting means on said member, an adjustable strut between said plate and member for retaining the member'in adjusted position, an eccentric anchor for one end of the strut, and means for adjusting the eccentric to effect minor angular adjustments of the member with respect to the plate.

5. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively movable in a predetermined plane, said attachment comprising a bed plate adapted to be secured to the work table, a base member supported on the bed plate, means providing for angular adjustment of the member on the plate about each of two parallel axes, a strut pivotally attached to the member at a point intermediate said axes and having an end thereof slidably supported in the bed plate, means for releasably securing said end to the plate, and work-supporting means carried by the member.

6. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively traversible in a predetermined plane, said attachment comprising a base adapted to be secured tothe work table, a structure mounted on said base for adjustment selectively about either of two pivotal axes parallel to said plane, means for supporting a work piece in said structure, and an adjustable seat for said structure intermediate said axes.

7. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively traversible in a predetermined plane, said attachment comprising a base adapted to be secured to the work table, a structure mounted on said base, detachable means for pivotally attaching the structure at each end to the base whereby the said structure may be tilted on the base about either of the two axes selectively, guide means on the base extending in a direction from one of said axes toward the other, a strut member pivotally attached at one end to the structure and adjustably secured at the other end on said guide, and work supporting mean carried by said structure.

8. An attachment for surface grinders of the type including a rotary grinding tool and a work table relatively traversible in a predetermined plane, said attachment comprising a base adapted to be secured to the work table, a structure mounted on said base, detachable means for pivotally attaching the structure at each end to the base whereby the said structure may be tilted on the base about either of the two axes selectively, guide means on the base extending in a direction from one of said axes toward the other, a strut member pivotally attached at one end to the structure and adjustably secured at the other end on said guide, and means on said structure for mounting a work piece for rotation about an aaasase .axis extending generallyinthe direction rot said guide.

2.9. Anattachmentiforsurface grinders bfthe typeiincludinga rotary grinding tool and a work table :relatively 'traversible in :;a, predetermined plane,r;said, attachment comprising :a' base "adapted to bersecured to the work table,a structure mounted on,:said base, detachable means for "pivotally attaching the structure at each end to the base -=whereby the saidstructure ,may be tilted on theabasenabout:eithercf the two axes zselectively, guidezmeansion the base extending inadirection .fitom.,.one of said'axestowardzthe other, a strut member pivotally "attached at one end to the structure and adjustably secured at the other end on said guide, means-on-said structure ;:for

mounting a workg piecefor .rotationabout an axis extending generally inthe direction of said'guide, and means;carriedaby-said: structure ifor rotating said-workpiece.

110. "An attachmentior surface grinders of the type including arrotary grinding tool and'a-zwork table :.relatively traversible in a predetermined p'lane,::said=attachment comprising a base adapted-to'bexsecured to the work table, a'structure mounted on said base; means for attaching the structure'to the base for tilting-adjustment about each'of'two parallel axes in the base remote from eachpthen-meansfor maintaining the said structure rigidly in the adjusted positions about each of:said; axes, means for supporting awork piece onsaid structure ,for rotation about an *axis in a rplane normal :to said parallel axes, and means forrrotatingthe work.

11. An attachmentffor; surface grinders of the typeincluding :a rotary grinding-tool and a work table relatively traversible .in a predetermined nlane,;said attachment comprisinga-base adapteditmbesecured to the work tab1e,'a second work tablennounted on the base'fortilting adjustment aboutga predetermined axis, means for:mounting a-work piece on the last-named table for rotation about anraxis ina planenormal to said axis of :tilt and substantiallyparallel ,to'the plane of said table, a motor bracket-pivotedto the structure 10f said-second table on an axisparallel to the-;axis;of rotation of-the workpiece, a motor secured to said bracket, a drive pulley on said motor, and :means for operatively connecting the motorwith the work, said means including a drive belt engaged with said pulley and constituting asuspension means for the bracket.

-.12. An attachmentfor surface grinders of the typeincluding a rotary grinding tool and a. work table traversible relatively in a predetermined plane, said attachment comprising a base adapted .to be secured to the work table, a structure mountedon said base for pivotaladjustment selectively about either of two pivotal axes parallel to said plane, means for supportinga Work piece in-said structure for rotation about a predeterminedaxis in the lattenand a strut element attached to and operating between said base and said structure to support the structure rigidly in theadjusted positions about each of said axes,

said strut being itself adjustable to opposite sides of an approximate center line in said structure located'between and paralleling said axes so as to provide for location of the strut in afavorable position with respect to the axis about which the structure has been adjusted.

'13. An attachment for a grinding machine havinga, rotating tool and a work table relativeli traversible in a predetermined plane, said attachment comprising a base adapted to be secured to the work table, a structure mounted on said base,'means for attaching the structure to the base for tilting adjustment about each of two parallel axes fixed with respect to said base'and remote from each other, means for maintaining the said structure rigidly in an adjusted position about either of said axes, means for supporting a work piece on said structure for rotation about an axis in a plane transversely intersecting said parallel axes, and means for rotating the work.

14. An attachment for a grinding machine having a rotating tool and a Work table relatively traversible in a predetermined plane, said attachment comprising a base adapted to be secured to the work table, a structure mounted on said base, means for attaching the structure to the base for tilting adjustment of the structure about either of two axes fixed with respect to the base, means for maintaining the said structure rigidly in an adjusted position about either of said axes, means for supporting a work piece on said structure for rotation about an axis extending in a direction transverse to said first mentioned axes, and means for rotating the work.

15. An attachment for a grinding machine having a rotating tool and a work table relatively traversible in a predetermined plane, said attachment comprising a base adapted to be secured to the Work table, a structure mounted on said base, means for attaching the structure to-the base for tilting adjustment of the structure-about either of two axes fixed with respect to the base, means for maintaining the said structurerigidly in an adjusted position about either ofsaidaxes, means for supporting a work piece onsaid-structure for rotation about an axis extending in a direction transverse to said first mentioned axes, means for rotating the work, and means'for immobilizing the work piece in predetermined positions of angular adjustment about itsrotative axis.

CHARLES W. STRONG.

REFERENCES CITED The following references are of record'in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,845,172 Morey et a1. Feb. 16, 1932 376,814 Coleman ,Jan. 24, 1888 1,367,522 Bernard Feb. 1, 1921 1,749,328 Einstein et al Mar. 4, 1930 2,214,166 Hertlein Sept. 10, 1940 

